This repo demonstrates how to do introspection of C and C++ messages.
The dynmsg package can convert ROS 2 messages into a YAML representation, and convert a YAML representation into ROS 2 messages.
The initial development of this code (with support for C messages) was graciously supported by Rocos (@rocos.io). C++ messages support was added by Christophe Bédard.
The dynmsg_demo package contains a demonstration of how to do dynamic introspection of messages using the rcl message API.
For a C message, see conversion.c.
For a C++ message, see conversion.cpp.
For more examples, see the message conversion tests for dynmsg.